Am I On The Right Track (bad pun, sorry!)

[UK78ALUM]

The newbie is back.  I've done my homework and gotten the books suggested in the prior thread of mine, and I'm literally devouring them as we speak.  And just maybe I'm on the right track here -  or at least I'm learning what questions to ask.  So here's my next one....

I am going to run the McKinley Explorer cars on my Alaska line, and in fact I already have 4 of the Bachmann Silver Series.   Now as to the math involved here....given that they are scale models of an actual 80 foot rail car, they are obviously longer than anything else I have.

So, in that case, does either the radius of the curves or the angle of the grades (or both?) need to be considered for my layout where it would not otherwise normally come into play?   It seems almost intuitive to me that the curves are going to have to be less acute, but that's why I appreciate the advice of everyone here.

As always, thanks for your suggestions and ideas!

[markpierce]

For a "best practices" rule-of-thumb, see

http://www.macrodyn.com/ldsig/wiki/index.php?title=Curve_radius_rule-of-thumb

Mark

[markpierce]

For vertical curves connecting grade changes, I'm not aware of a similar rule-of-thumb, but the rate of change is probably less than you think for reliable operation.  I never had a problem, but I have always used 1/2-3/4-inch plywood for the track base and only bent it gently for vertical grades. 

Mark

[Texas Zepher]

I am going to run the McKinley Explorer cars on my Alaska line, and in fact I already have 4 of the Bachmann Silver Series. ....given that they are scale models of an actual 80 foot rail car.....in that case, does either the radius of the curves or the angle of the grades (or both?) need to be considered for my layout where it would not otherwise normally come into play?  It seems almost intuitive to me that the curves are going to have to be less acute

Your intuition would be correct; however, there are some other considerations.  The Bachmann cars have been designed with sharp turns in mind so they should negotiate an 18" radius curve.  They will overhang on both sides of the rails substantially more than other shorter equipment.  If there is any scenery close to the track it might have to be moved back.

Likewise the grades themselves should not be an issue, but the transition between different grades can cause coupling issues.  As one would expect the vertical motion of a coupler on the end of a long car is greater than that of a short car.   Coupler height is more critical on long cars.  This is even for bumps in the rail.  The more dramatic the change from a flat track to a grade the bigger the issue will be.  This is not an issue if the couplers are truck mounted, but I believe the Bachmann couplers are mounted on the body.

All of that is operational.  As for how well the car looks it is a different story.  Obviously the longer the car the better it will look on big curves. In my opinion and 80 foot car begins to look OK on a 32" curve, it does look OK on 36", and starts to look "good" around the 44" radius range.  Curves this large can only be dreamed of by some people, so it need not be a show stopper.   Many people, especially non-model railroaders, will not notice the overhangs.   The only way to know for certain is to put a set of cars out on a curve of known size, look at them, and decide if you can live with the way they look.

[loathar]

I know their heavy weight cars were recommended for minimum 22" radius. Don't know if the McKinnleys are the same, but bigger is always better with long cars like that.
High 20's - low 30's would be needed if your going to add working diaphragms between the cars.

[jeffrey-wimberly]

Something I did on my current layout was to use an Athearn streamline passenger car to map the overhang and end throw on the curves and turnouts. This way I knew exactly how close I could come to the track with trees, poles, structures, etc. BTW, all my curves are 18" radius and the turnouts are #4's and #5's so I usually don't run any cars over 60' in length, with the exception of my tourist train which is a string of Athearn heavyweights pulled by a Mehono 2-10-2 steam locomotive. Your McKinley Explorer cars will run on 18" radius but they look horrible doing it. If you have a choice don't go below 24" radius. In my case I didn't have a choice. Space is at a premium and N Scale is totally out of the question.